A variety of appliances, such as mobile phones, set-top boxes, electrocardiogram (ECG) monitors, and music systems suffer from noise, due to which a useful signal gets distorted. Background or ambient noise is generally controlled using noise removal systems. Noise removal systems can include an active noise removal system, such as an active noise cancellation (ANC) system, and a passive noise removal system. While passive noise removal systems use unpowered techniques, such as insulation or sound absorbing ceiling tiles or mufflers, the active noise removal systems use powered systems for the removal of the background noise.
The active noise removal systems generally include an analog-to-digital converter (ADC) due to which quantization noise is also introduced in a digitized output signal. Quantization noise is the difference between an actual value of an analog input signal and the corresponding digitized output signal. Generally, different techniques, such as oversampling and dithering, are used to reduce the quantization noise. However, such techniques are usually inefficient and also result in a loss of signal reliability. Further, in an ANC system, generally an anti-noise signal having the same amplitude, but an opposite phase to that of the noise signal is used to cancel the noise signal. However, this leads to a loss of fidelity and overall signal energy.